Mission: Take a technical lead role and help shape the future of the product. You'll own the core backend, drive robustness and scalability, and anticipate performance bottlenecks as we scale and face complex technical challenges.What you'll tackle:- Async APIs at scale: Design and scale fast, async APIs with FastAPI & Pydantic- Durable workflows: Build crash-proof workflows — durable, reliable, production-grade- Database performance: Optimize Postgres DB performance at scale- Infrastructure edge cases: Solve hard infra problems: resource fairness, throughput, edge cases- Observability ownership: Own observability and performance monitoring end to end- AI backend foundations: Push the boundaries of backend infra powering AI featuresOur stack: Python 3.13+, FastAPI, Pydantic, Postgres, AWS, Terraform, Docker, Hatchet / Temporal, Sentry, PostHog, Next.js, Pyright (strict)About you: MSc in Computer Science or similar; 6+ years backend experience; strong Python and system design; deep understanding of algorithms, async programming, and SQL; proficient with Docker, CI/CD, and cloud (bonus: AWS); strong leadership and mentorship; security-conscious practices (nice to have); experience with LLM infra and RAG (nice to have).Interview process: Apply (hello@cominty.ai) → Intro call (with our CTO) → Technical assignment → Final chat (with co-founder).What Cominty offers: High-impact role; direct founder collaboration; rapid career growth; modern work environment (2–4 days remote/week); attractive compensation.